The big tease turns into the long goodbye in “The Twilight Saga: New Moon,” the juiceless, near bloodless sequel about a teenage girl and the sparkly vampire she, like, totally loves. When last we saw Bella (Kristen Stewart) and her pretty dead guy, Edward (Robert Pattinson), in “Twilight” — the series hadn’t been saga-fied yet — the two had pledged their troth, a chaste commitment solidified during moody walks in the woods, some exhilarating treetop scrambling and a knockdown fight with a pack of vamping vampires.

But love is cruel and sometimes so too are multivolume juggernauts like Stephenie Meyer’s “Twilight” series, which, because they need a prolonged shelf life, are as much about narrative delay (and delay) as release and resolution. That’s particularly the case here given that Edward belongs to a stylish vampire clan that has given up human blood in order to live, if conspicuously out of place, in a Washington town called Forks. Abstinence is the name of this franchise’s clever game — a demographically savvy strategy that the filmmakers exploit with a parade of bared male chests — which is why Edward refuses to stick his teeth in Bella’s unsullied neck, despite her increasingly feverish pleading.

The problem, already evident in the first movie, is that a vampire who doesn’t ravish young virgins or at least scarily nuzzle their flesh isn’t much of a vampire or much of an interesting character, which initially makes Edward’s abrupt and extended disappearance from the second film seem like a good idea. “New Moon” opens with a seemingly content Bella turning 18, a happy occasion that takes a frightening turn during a party at Edward’s house. While the rest of the vampires ghoulishly beam at her with their amber cat eyes, Bella accidentally pricks her finger while opening a gift, sending a drop of blood onto the carpet and one of the less-repressed vampires, Jasper (Jackson Rathbone), into a violent frenzy.

Edward saves Bella, but soon decides to split town. Dead or alive, men can be brutes (authors too): he also tells her that she’s not good for him, leaving her bereft. This act of cruelty throws her into a long depression that the director Chris Weitz (“The Golden Compass,” “About a Boy”), having taken the filmmaking reins from the sloppier if more energetic Catherine Hardwicke, tries to translate into cinematic terms, mostly by circling Bella with the camera as the months melt away. Ms. Stewart’s darkly brooding looks are convincing, but her lonely-girl blues soon grow wearisome, as does the spinning camera. Happily, there’s another attractive diversion in the wings in the form of her friend Jacob (Taylor Lautner), a member of a mysterioso Indian tribe, who brightens her mood with his blindingly white smile.

Jacob has secrets of his own that soon emerge, first in the form of some massive biceps. My, what big muscles you have, Bella tells him, nicely exposing her inner wolf. Alas, Bella, whose palpable hunger for Edward gave the first movie much of its energy and interest, has been tamped down for “New Moon,” partly because she’s in mourning, though largely because a ravenous female appetite wouldn’t work with this story’s worldview. (Melissa Rosenberg’s screenplay is dutifully subservient to the source material.) So, while Jacob’s body grows harder and harder before Bella’s widening eyes, she looks — mirroring the audience’s appreciative gaze — but doesn’t at first touch. Even when they start fixing up some old motorcycles, hands brushing and engines gunning, the relationship remains safely in neutral.

Bella, of course, belongs to Edward, who, though physically gone, hasn’t left the picture. Every so often he materializes in hazy, semi-transparent form to caution her about something, much as Woody Allen’s fictional mother does when she nags from the sky in “New York Stories.” Realizing that her vampire has gone guardian angel on her, Bella, like a classic crazy ex, begins throwing herself into ever more dangerous situations to summon him. Although this perks up the slack proceedings, the spectral image of Edward only underscores how damaging it is to separate Romeo from Juliet, even if there’s a hormonally revved-up teenage wolf lurking in the shadows. Chastity is only hot, after all, when it seems like it actually might be violated.

There’s more — the book is another doorstopper — crammed between the weeping and dolorous gazes, including a pack of snarling, not terribly effective CGI wolves. They’re amusing if not as diverting as either Dakota Fanning or Michael Sheen, who pop up in a late-act detour to Italy, where the vampires, unlike their puritanical American cousins, still like to drink. (In a rare moment of narrative wit, Bella flies Virgin.) Mr. Sheen, who’s carved out a twinned specialty playing Tony Blair and werewolves, preens with plausible menace. But it’s Ms. Fanning, with the cruel eyes and sleekly upswept hair suggestive of an underage dominatrix, who shows real bite. Mr. Weitz doesn’t know what to do with her, but when she smiles, you finally see the darker side of desire.

Directed by Chris Weitz; written by Melissa Rosenberg, based on the novel “New Moon” by Stephenie Meyer; director of photography, Javier Aguirresarobe; edited by Peter Lambert; music by Alexandre Desplat; production designer, David Brisbin; produced by Wyck Godfrey and Karen Rosenfelt; released by Summit Entertainment. Running time: 2 hours 10 minutes.

A film review on Friday about “The Twilight Saga: New Moon,” in which the actor Michael Sheen appears, misidentified the creature he has played in other films. It was a werewolf, not a vampire.

A version of this review appears in print on November 20, 2009, on page C1 of the New York edition with the headline: Abstinence Makes the Heart ... Oh, You Know. Order Reprints|Today's Paper|Subscribe